LVIV, Ukraine (Reuters) - Ukraine's south-eastern port of Mariupol was under constant shelling from Russia and unable to evacuate the injured while Kherson, on the Black Sea to the west, was completely surrounded by invading forces, Ukrainian authorities said on Wednesday.

       "We are fighting, we are not ceasing to defend our motherland," Mariupol mayor Vadym Boichenko said live on Ukrainian TV.

       (Reporting by Pavel Polityuk, Writing by Gabriela Baczynska, Editing by Andrew Heavens)